1. Field of the Invention
The present invention is in the field of aerodynamics and specifically relates to a rotating airfoil that could be used, for example, as a wind motor to generate a torque; or alternatively, it could be driven to serve as a propeller or lift-generating device.
2. The Prior Art
In U.S. Pat. No. 1,697,574 issued Jan. 1, 1929, Savonius describes a rotor that now bears his name. In his own words, "the vane rotor consists of two oppositely arranged hollow shaped vanes of predominantly rectilinear generatrix, the inner edge of each vane catching the segmental space bordered by the other vane, both vanes thus forming an air passage being adapted to force the air current from the hollow side of one of said vanes to the hollow side of the other vane in an S-like passage of substantially constant area."
Today, to workers in this field, the term "Savonius rotor" suggests a family of structures characterized by two cylindrical-shaped sheets, disposed symmetrically about an axis of rotation, with their concave surfaces facing each other. A number of variations have been tried; typically they involved altering the separation between the vanes or using the centrifugal force resulting from rotation of the rotor to alter the shape of the vanes to automatically limit or control the rotational speed. Such a technique is described in U.S. Pat. No. 1,766,765 issued Jun. 24, 1930 to Savonius.
The present invention is not merely another variation of the dimensions of the rotor. Instead the present invention consists of a new and beneficial vane shape that improves the performance of the rotor.